The invention relates to a thin-strip casting device comprised of a pair of casting rollers that oppose each other and are approximately identical. The casting rollers form a funnel by means of lateral seals for receiving the steel melt.
Thin-strip casting devices, in particular two-roller casting devices for producing hot-rolled wide strip material in the usual width range of about 800 to 1400 mm and a thickness range of about 2 to 5 mm normally found in such a production, are known in practical life. Casting rollers with a constant diameter and variable lengths of their shells are normally employed because the width of the strip material is substantially determined by the length of the shell of the casting rollers.
However, in the planning of a steel plant in the form of a mini-foundry with an annual production capacity of about 400,000 to 500,000 tons, which is installed upstream of the thin-strip casting plant and continuously supplies the latter with steel melt, the production of the steel foundry is practically constant. Therefore, the steel plant is operating economically only if at least three to five charges are poured as xe2x80x9cconti-contixe2x80x9d casts. This means that the steel foundry has to be planned and designed in such a way that it is capable of supplying the thin-strip casting device with steel melt in a continuous manner when the maximum strip width is desired. However, it must also be accepted in the case where the steel foundry is operated with artificially prolonged charging times when small strip widths have to be produced. This fact, however, impairs the economy of the production facility as a whole.
The object of the invention is to increase the capacity of existing thin-strip casting devices that are already operating within their limit ranges, with low technical expenditure in terms of machinery and with justifiable investment expenditure. The objective is to avoid the drawbacks of the prior art described above to the extent that a thin-strip casting device is provided that assures an about constant production of thin-strip material over the entire selected width range, without requiring artificially prolonged charging times of the steel foundry installed upstream.
The problem is solved by a multitude of pairs of interchangeable casting rollers associated with the thin-strip casting device. These casting rollers have different casting roll diameters depending on the strip widths to be cast.
In an advantageous embodiment of the invention, each pair of casting rollers has a shell length defined by the strip width. A defined casting roll diameter is chosen whereby the product of the shell length and the casting roller diameter xe2x80x9cDxe2x80x9d of the casting rollers of all interchangeable pairs of casting rollers is approximately the same.
According to a useful further development of the invention, the pairs of casting rollers each are pre-installed in a changing frame.
Compared to known devices, the proposed thin-strip casting device offers a substantial advantage in that it assures without much technical expenditure a constant production of thin-strip material in any customary width range and thus an economical operation of the steel foundry operating upstream.